1. Field of the Invention
The present invention relates to a voice input apparatus, and particularly to apparatus for removing noise from among the sounds collected by a microphone.
2. Related Art
As a method for providing various operating instructions to a vehicle-mounted apparatus, for example, a navigation system or an audio device, in addition to a manual method in which a user pushes down various keys installed on an operating panel or a remote control unit (remote controller), there is a method performed by recognizing the contents of a user's voice. When an operating instruction is provided by means of a voice recognition apparatus, it is not necessary to remember the placement or the like of operating keys. Furthermore, it is possible to simplify the operation because a key operation is saved while the vehicle is moving during driving. Especially in recent years, its use is often found in a vehicle-mounted apparatus along with high-speed processing capability.
Typical factors lowering the recognition rate of such a voice recognition apparatus are road noise, car noise inside the vehicle caused by an engine or the like while driving, and audio sound produced from an audio apparatus inside the vehicle. When these noises and the audio sound are superimposed on the voice of a user, it becomes difficult to correctly perform voice recognition because the voice recognition apparatus cannot discriminate and process only the voice of the user from among the various sounds. Conventionally, contrivances have been made to reduce the various noises and the audio sound superimposed on a voice signal targeted for voice recognition such that road noise is reduced by means of the art of adaptive microphones array, or an audio sound output is interrupted or its volume is lowered when a talk switch is pushed down.
However, when measures are taken to interrupt an audio output or lower the volume level of the audio by depressing a talk switch, there is a problem of hindering a user's listening because the audio sound is interrupted when the voice recognition processing is performed frequently. In particular, a passenger other than a user who is operating the vehicle-mounted apparatus by voice input may be listening to an audio sound and feel disturbed when the audio sound is frequently interrupted. Therefore, a method is desired which can extract an input voice without interrupting generated audio sounds.
The present invention is made to address these points and its object is to provide a voice input system which can extract an input voice without interrupting generated sounds.